The BSD family of operating systems date all the way back to the 1980s when AT&T owned the legal rights to the OS known generically as "Unix". During that time, the source code was licensed out to a few communities, each of which developed their own proprietary version. One of the versions was BSD-Unix, named after the University of Berkeley. Due to license agreements with AT&T when Berkley tried to release their BSD-Unix for free, AT&T sued. The outcome of that lawsuit was the creation of BSD/OS, which was basically AT&T/BSD Unix with the proprietary AT&T code removed. Later on the commercial BSD was branched into what is today FreeBSD. FreeBSD currently runs on the Intel and Alpha architectures, with ports to Arm, Itanium, PowerPC and Sparc on the works.

FreeBSD uses the BSD license. With a BSD style license, you are not required to make your changes to the source available to the public. In fact, you can take BSD licensed code, and make it into a commercial proprietary product. This is what Apple has done with OS X, and it seems to be working out well. It's also working out well for FreeBSD as Apple has hired Jordan Hubbard, one of the founders of FreeBSD. This is in contrast to the license Linux is distributed under, the GPL. This copyright does not allow you to make proprietary changes to the source code.

The install routine for FreeBSD is nothing like the Mandrake or Red Hat installations. Probably the closest thing to it in the Linux world would be Slackware. FreeBSD has no graphical partitioning tool, you're expected to use fdisk and disklabel. There is no "linuxconf" type application; upon booting it the first time you're handed the root login and vi (or emacs if you choose to install it), and the ports tree (or pkg_add) to install software. There are some text-based apps for configuring network settings and such things, included in /stand/sysinstall. That however is about the extent of FreeBSD's "hand-holding".

On the other hand, in some ways FreeBSD is more mature than Linux, due in part to the fact that it is based on BSD, which has been in existence since the mid-80's. Because of this, it has had more time to work out existing bugs. It also has something to do with the maintainers sacrificing the latest and greatest features for wonderful stability and robustness. FreeBSD is reputed to be one of the most robust and stable operating systems on the x86 platform. In fact, go to netcraft.com. Notice that the top 13 servers with the longest uptimes are all either BSD/OS or FreeBSD. It currently has support for IP version 6 addresses (the internet currently uses IP v4), multi-processor capabilities, reliable TCP networking, true multi-tasking, and has binary support for Linux, SCO Unix, and BSD/OS, and NetBSD, which means that if a specific application hasn't been natively ported to FreeBSD, it can still run it as if you were running a different OS!